In New Mexico, lung cancer incidence and mortality rates are markedly different in the Hispanic and non-Hispanic white (Anglo) populations. Among males, Hispanics have lower rates at all ages with an overall incidence approximately one-third that of the Anglos. Among females, the overall rates are similar but Hispanics have lower rates at younger ages, and higher rates at older ages. A population-based case-control study is in progress with the objective of explaining these known differences in lung cancer occurrence. Secondary objectives include an assessment of lung cancer risk factors in a population-based case series with emphasis on cigarette type, occupation, passive exposures, and dietary vitamin A. A review of the histopathology of 1980-83 cases and of 1970-72 cases is also in progress. The results will be used to assess temporal changes in lung cancer histopathology and to conduct histology-specific analyses in the case-control study. Through 1/15/83, interviews have been completed with 442 cases and 787 controls. An additional 78 interviews with 1980-82 cases are anticipated. Plans for analysis and related computer programming are nearly complete. This application requests two years additional support for this project. During the first year, 131 additional interviews will be conducted with Anglo female, Hispanic female, and Hispanic male cases to increase statistical power in these groups. The histopathology review and data analysis will be completed during these two years, as well. This investigation will provide new information concerning the epidemiology of lung cancer in Hispanics. Additionally, established and putative risk factors will be examined in a population-based study.